5-cyanomethylene-2-oxo-3-pyrrolines



@ ice 3,013,013 ,5-CYANQMETHYLENEQ-6X0=3-PYRROLINE Rudolph A. Carhoni, Wilmington, DeL, assignor to E. I. du Pont de Nernonrs and Company, Wilmington, Del,

a corporation t Delaware No'Drawing. Filed Apr. 24, 1959, Ser. No. 808,537 "8 Claims. (.Cl. 260-246) The present invention is concerned with a new class of colored organic chemical compounds which are useful as dyes and more particularly deals with -substituted-2-oxo- 3-pyrrolines.

In the family of dyes of this invention, the presence of a substituted methylene group at the 5-position in the 2-.oxo-3pyrroline ring is associated with a generic superiority in light fastness over related dyes having a chalcogen atom in place of the substituted methylene group.

The new class of dyes comprises the S-cyanomethylene- 2-oXo-3-pyrrolines. These are generically new compounds. The S-cyanomethylene-Z-oxo-3 pyrroline nucleus is fundamental to the characteristic property of these compounds of being visibly colored. This characteristic carries through the entire class of compounds.

The S-cyanomethylene-Z-oxo-3-pyrroline dyes particularly embrace (A) the 5-cyanomethylene-2-oXo-3-pyrrolines in which the 4-position and the remaining (0c) position-of the methylene carbon atom carry members of the group consisting of CN, SO R, -COOR and CONR in which R is hydrogen or a hydrocarbyl group and the 1-position carries an R group.

The dyes of group A in turn embrace (B) the compounds of group A in which the 3-position carries an R group; (C) the compounds of group A in Which the 3-position carries a halogen radical (particularly chloro and bromo) and (D) the compounds of group A in which the 3-position carries a group Q which is a monovalent organic radical such that the corresponding compound QH will condense with benzene diazonium chloride to yield an azo dye.

The compounds of group C are particularly useful for preparing the dyes of group D and this invention embraces the process of reacting a compound of group C with a compound QH to obtain a dye of group D. The dyes of group D are preferred over the methylene-2-oXo-3-pyrrolines of this invention for their stronger colors and superior dyeing properties. These dyes may be represented by the formula where R is hydrogen or a hydrocarbyl group, X and X maybe -CN, AO R, COOR or CONR and Q is a mouovalent organic radical such that the corresponding compound QH will condense with benzene diazonium chloride to yield an azo dye, i.e., C H N=N-Q.

The definition of the radical Q can be readily understood from the fact that the 3-halogen compounds of group C above have the same color formers (i.e., compounds QH) as the aryl diazonium halides. The coupling reactions of the aryl diazonium salts are well known to all dye chemists. They are discussed in detail by K. H. Saunders in The Aromatic Di azo Compounds and Their Technical Applications, Edward .Arnold & Co., London, Second edition, 1949, particularly pages 194-219.

The definition of Q is based specifically on the reactivother 5-cyano-- capacity for coupling with Patented Dec. 12, 1 9-51 ity of benzene diazonium chloride for present purposes partly because benzene diazonium chloride is the simplest and most available of the aryl diazonium halides and partly because this means serves to point out that hydrocarbon compounds such as benzene and monoalkoxy benzenes are not included among the color formers which yield the preferred dyes of group D. Benzene and anisole Will react with certain highly activated aryl diazonium halides but not with benzene diazonium chloride to yield azodyes.

To fit the above definition of Q, acompound QH must be capable of reacting with benzene .diazonium chloride to yield an azo dye, i.e., a compound C l-I -N=NQ. The test to determine reactivity with benzene diazonium chloride may be conducted very simply as follows:

Benzene diazonium chloride test reagent is prepared by treating one molecular equivalent of aniline with 2.7 molecular equivalents of hydrogen chloride as a concentrated aqueous solution. This and treated with one molecular equivalent of sodium nitrite, dissolved in twice its weight of water. The addition of the nitrite solution is carried out at a rate so that the temperature does not exceed 5 C.

Ten milligrams of thecompoundQH to be tested is dissolved in 1-2 ml. of acetone and to this solution is added about 0.25 g. of sodium acetate. The latter is preferably ground to a fine powder. One to three drops of the diazonium solution is added to the test mixture. When QH contains an electron-donating group or is an active methylene compound, the addition of the benzene diazonium chloride causes the immediate formation of an azo dye ranging in color from deep orange through red, purple, to green. An alternative way of expressing the result is that there is formed an azo compound having at least one absorption peak between 350 and 7 50 millimicrons.

Compounds which react positively to the benzene diazonium chloride test above, i.e., cornpounds which fit the definition of QH, include principally those compounds containing electron-donatinggroups and compounds containing active methylene groups. I groups are auxochrome and chromophore groups ;well known to dye chemists such as -OR, NR2 andother organic radicals with bonds stemming from nitrogen, ;R beinghydrogen or a hydrocarbyl radical as defined above, and electronic equivalents of these groups.- Particularly included QH compoundsare aromatic compounds con in which Ar is arylene; R" is hydrogenor-hydrocarbyl; and R is ,hydrocarbyl, B-alkoxyethyl, fi-acyloxyethyl, B-cyanoethyl or B-trialkylammoniumethyl; .Y and Y' are solution is cooled to 0 C.

Electronrdqnating -CN, -COOR, -COR, CONR -CSNR -SO R, -NO -NR and SR Z is alkyl, halogen, -SO Na or Y; Z' is hydrogen or Z, with the proviso that Z and R" taken together may form another aryl ring; and n is or 1. It is to be understood that in a given compound the several embodiments of R and R' that may be involved may be the same or different, respectively.

By arylene I mean generically any divalent aromatic radical. It is of the essence of an arylene radical that the two bonds stem from different ring carbon atoms.

Among arylene-radicals are included those from which the corresponding aromatic compound obtained by placing hydrogens at the respective bonds of the arylene group has a resonance energy of not less than 20 kcal./mole. Resonance energies of organic compounds and the determination of resonance energies are shown by Linus Pauling in The Nature of the Chemical Bond, Second edition, Cornell University Press, 1945, pages 132-139.

Arylene groups particularly suitable in the compounds of this invention include phenylene, naphthylene, anthrylene, furylene, thienylene, and pyrrolylene.

By the term hydrocarbyl, used in defining the products and process of this invention, I mean any monovalent organic radical composed solely of carbon and hydrogen. I use it in its full generic sense. The wide variation in the hydrocarbyl groups used in the illustrations which follow makes it evident that all hydrocarbyl groups are operable. Hydrocarbyl groups can vary as to whether they are saturated, unsaturated, alkyl, cycloalkyl, aryl, aralkyl, alkaryl, single ring, multi ring, straight chain, branched chain, large, small and the like. The widest variation of this sort does not in any way detract from the. fundamental characteristic of the hydrocarbyl radical of passing unchanged through the process of this invention, and exercising no effect whatever on the chemical steps of the process.

The limitations of space for disclosure are not to be construed as any limitation within the scope of hydrocarbyl contemplated in this invention. Even the most cumbersome hydrocarbyl radicals such as those obtained by removing end groups from high molecular weight bydrocarbon polymer molecules containing thousands of carbon atoms, such as polyethylene, polyisobutylene, polyisoprene, polystyrene and the like, are fully operable.

It is obvious that hydrocarbyl groups containing 20 or fewer carbon atoms are most available, and to that extent preferred. But there is to be no question of the operability of, or of the intent to include and disclose any hydrocarbyl group whatsoever. Except for factors of bulk and dilution, wide variations in size and structure of hydrocarbyl radicals have no effect on thecolor of the S-cyanomethylene-Z-oxo-S-pyrroline dyes to which they are attached. All 5-cyanomethylene-2-oxo-3-pyrrolines obtainable by variation of hydrocarbyl groups within the above definitions are hereby disclosed. Routineering to disclose each and every possible hydrocarbyl embodiment is superfluous. I

1 The process of this invention may be illustrated by the equation where (hal) is halogen, i.e., fluorine, chlorine, bromine and iodine.

In the above process it is not necessary to isolate the 3-halogeno starting materials. As illustrated in the examples the halogen intermediates may be used for the preparation of dyes without isolating them from the media in which they are prepared. The 3-halogeno starting materials are conveniently prepared by treating the sodium salt of the corresponding B-hydroxy compound with a strong halogenating agent such as phosphorus oxychloride, thionyl chloride, oxalyl chloride, benzotrichloride, benzene sulfonyl chloride, phosphorus tribromide, phosphorus oxybromide, thionyl bromide and the like.

As indicated by the wide variations in the examples, there are no process variables which appear critical. As shown in the examples, it suffices to bring the reactants together and no auxiliary materials are required.

It is convenient, although not essential, to employ as a reaction medium an organic solvent which is inert to the reactants and products. Thus, there can be employed aliphatic or aromatic hydrocarbons, dialkyl ethers, cyclic ethers, such as dioxane and tetrahydroiuran, esters, N,N- dimethylformamide, N,N-diethylformamide, N-methylformanilide, N-methylforrnamide, formarnide, N-methyl- N-ethylacetamide, N,N-dimethylacetamide, N,N-diethylacetamide, tetramethylurea, tetraethylurea, pyridine, dimethylsulfoxide, 2,2,2-trifluoroethanol, acetonitrile, and mixtures of these liquids. Esters and alkanenitriles are the preferred class of solvents. Since the reaction of this process is mildly exothermic, the use of an inert reaction medium facilitates dissipation of the heat of reaction.

The temperature at which the reaction of this invention is carried out may be varied widely, for example, from temperatures below 0 C. up to the decomposition temperature of the reactants or products. In general, however, it is preferred to operate in the range of 0200 C., and best yields are obtained when operating in the range of 20-100 C.

The reaction of a 5-cyanomethylene-2-oxo-3-pyrroline with a compound Ql-I according to this invention takes place between equimolecular quantities of the reactants. However, this in no way limits the molar proportions of these reactants which may be brought together within the limits of the process. The relative amounts may be varied widely, for example, from molar ratios of 19:1 to 1:19. However, highest yields are obtained when approximately equirnolar quantities are employed.

Pressure is not a critical variable in this process, and atmosphericpressure is ordinarily preferred for convenience, although pressures above or below atmospheric are operable.

In the following examples parts are by weight unless otherwise indicated. Example V represents a preferred embodiment of the invention. 7

' EXAMPLE I Part A A solution of 132 parts of malononitrile dimer [C(CN) =C(NH )CH CN, Carboni et al., I. Am. Chem. Soc. 80, 283840 (1958)] and 160 parts of diethyl oxalate in 793 parts of absolute methanol is added quickly to a solution of 108 parts of sodium methoxide in 595 parts of absolute methanol. The solution becomes warm and turns yellow. It is stirred at room temperature for two hours. About one third of the methanol is removed by distillation. The mixture is diluted with two volumes of dry benzene. The yellow precipitate which forms is collected by filtration to yield 203 parts of the disodium salt of 4-cyano-5-dicy-anomethylene-3-hydroxy-2-oxo-3- pyrroline. This salt is purified by recrystallization from /10 n-propyl alcohol/water.

Analysis.Calcd. for C N O Na Na, 19.99. Found: Na, 19.60.

Part B The disodium salt of 4-cyano-5-dicyanomethylenc-lihydroxy-2-oxo-3-pyrroline is dissolved in a minimum of water and treated with a molecular excess of aqueous hydrochloric acid. The dihydrate of the corresponding 'rnonosodium salt is obtained as a bright yellow precipitate EXAMPLE II Part A NHz GN To a solution of 23 parts of sodium in 3947 parts of ethanol at C. is added 390 parts of p-toluenesulfonyL acetonitnle. The mixture is then heated at reflux for 2.5 hours and allowed to stand over night at room temperature. The solution is diluted with 20,000 parts ofwater and carefully acidified with concentrated hydrochloric acid. p-Toluenesulfonylacetonitrile dimer (2-aminolcyano-1,3-di[p-toluenesulfonyl]propene) separates as a crystalline precipitate. This is separated by filtration and recrystallized from ethanol. Yield 245 parts, M.P. 194.5- 195.5 C.

Analysis.Calcd. for C H N O S c, 55.38; H, 4.62; N, 7.18; S, 16.41. Found: C, 55.54; H, 4.61; N, 7.70, 7.38; S, 16.56.

Part B ethanol is added 700 parts of p-toluenesulfonylacetonitrile dimer and 263 parts of diethyl oxalate. The resulting solution is stirred and heated at reflux for 1.25 hours, then diluted with 8794 parts of benzene and filtered to obtain 540 parts of the bright yellow crystalline disodium salt of 5-(a-cyano-a-p-toluenesulfonyl)methylene 3-hydroxy-Z-oxo-4-p-toluenesulfonyl-3 pyrroline. This is suspended in 5000 parts of water and 357 parts of concentrated hydrochloric acid is added slowly with stirring. There is precipitated 410 parts of the pale yellow crystalline monosodium salt of 5-(a-cyano-ot-p toluenesulfonyl') methylene-3-hydroxy-2-oxo-4-p-toluenesulfonyl 3 pyrroline.

EXAMPLE III HaC To a mixture of 10 parts of the dihydrate of the monosodium derivative of 4-cyano-5-dicyanornethylene-3-hydroxy-2-oxo-3-pyrroline and 191 parts of N,N-dimethylaniline about 25 parts of phosphorus oxychloride is added. The resulting mixture is heated at 80100 C. for a few minutes and turns blue-green in color with the formation of 4-cyano-5-dicyanomethylene-3-(p-N,N-dimethylarninophenyl) -2-oxo-3 -pyrroline.

Dyeing A A dyebath is prepared using 10,000 parts of water containing two partsof a sulfonated lignin dispersant (Marasperse CB, Marathon Co.) The bath is'rendered alkaline to pH 8 by adding 200 parts of 5% aqueous sodium bicarbonate solution. A solution of two parts of 4-cyano- S-dicyanomethylene-i(p-N,N dimethylaminophenyl) -2 oxo-3-pyrroline in 284 parts of N,N-dimethylformamide is added with stirring. The dyebath is heated at 80100 C. and swatches of cellulose acetate and nylon fabrics Weighing 10 parts each are added. After a few minutes the cellulose acetate is dyed red blue and the nylon is dyed medium brown. When the dyed fabrics are treated with 5% aqueous hydrochloric acid, both turn bright blue. They retain the bright blue color after rinsing and drymg.

EXAMPLE IV Preparation of 3-chl0r0-4-cyano-5-dicyanomethylene-2- oxo-S-pyrroline Fifty parts of the dihydrate of the monosodium derivative of 4-cyano-5-dicyanomethylene-3-hydroxy2 oxo-3 pyrroline is suspended in 157 parts of acetonitrile, and 60 parts of oxalyl chloride is added. The mixture is stirred and heated at reflux for one hour. The mixture is then cooled and the precipitate which forms is collected by filtration, washed with acetonitrile and dried under reduced pressure to obtain 36 parts yield) of crude 3-chloro-4-cyano-5-dicyanomethylene-2-oxo-3-pyrroline in the form of buff-colored crystals. It is purified by sublimation at C. and 0.1 mm. pressure to give colorless crystals.

Analysis.-Calcd. for C HN ClO: C, 47.06; H. 0.49; N, 27.45; Cl, 17.40. Found: C, 47.53; H, 0.77; N, 27.28, 27.46; Cl, 16.99, 17.04.

EXAMPLE V Analysis.Calcd. for C H N O: C, 66.4; H, 3.8.

Found: C, 66.2; H, 4.2.

EXAMPLE VI To a solution of 15 parts of 3-chloro-4-cyano-5-dicyanomethylene-Z-oxo-B-pyrroline in 450 parts of ethyl acetate is added a solution of 20 parts of l,1-bis(p-N,N dimethylaminophenyl)ethylene in 900 parts of ethyl ace tate. The mixture is allowed to'stand at room temperature for 1.5 hours. A precipitate of 28 parts of 4-cyano- 5-dicyanomethylene-3-[2,2 bis(p N,N dimethylaminophenyl) vinyl] -2-oxo-3-pyrroline is recovered by filtration.

It is recrystallized fromacetic acid and further purified by sublimation. |An ethanol solution of this dye shows an absorption maximumat 759 millimicrons.

Analysis-Calcd. for C H N O: C, 71.9; H, 5.1; N, 19.4. Found: C, 70.5; H, 5.0; N, 19.0, 18.8.

EXAMPLE VII i ON H The procedure of Example V is repeated using pyridine in place of ethyl acetate and benzoylacetanilide in place of N,N-dimethylaniline. The product is 3-['(.b..enzoyl) (N- phenylcarbamoyl)methyl]-4-cyano-S-dicyanomethylene-Z- oxo-3-pyrroline which gives orange ethanol solutions having an absorption maximum at 500, millimicrons.

1' EXAMPLE VIII ON Q E 1 l N N CH: 0 N/- -C\ To a solution of 204 parts of 3-chloro-4-cyano-5-dicyanomethylene-2-oxo-3-pyrroline in 1800 parts of ethyl acetate is added 88 parts of sodiomalononitrile. The sodium salt of 4-cyano-3-dicyanomethyl-5-dicyanomethylene-Z-oxo-S-pyrroline precipitates as a brick red solid. This dye (168 parts) is recovered by filtration and recrystallized from water. It gives orange solutions in water.

EXAMPLE X A mixture of 102 parts of 3-chloro-4-cyano-5-dicyanomethylene-Z-oxo-3-pyrroline and 184 parts of a-methyL furan in 945 parts of N,N-dimethylformamide is prepared and allowed to stand at room temperature for about 18 hours. The solution is then diluted with 2500 parts of water to precipitate 120 parts of d-cyano-S-dicyanomethylene-3-(S-methyl-Z-furyl)-2-oxo-3-pyrroline, a dark orange solid melting above 250 C. Solution of this product in ethanol and acetonitrile are bright yellow.

EXAMPLE XI i ON o Lo I 1 CN To a solution of 10 parts of 3-chloro'4-cyano-5-dicyanomethylene-Z-oxo-3-pyrroline in 1800 parts of ethyl acetate is added 5 parts of indole. The solution is warmed to S0-60 C. and within a few minutes 4-cyano- 5 dicyanomethylene 3 (3 indolyl) 2 L oxo 3 pyrroline forms as a bright red dye. Tht solution shows absorption maxima at 525 millimicrons and 370 millimicrons.

EXAMPLE XII --OHa N =CH 0N ON CH3 0: C\

\ ON H Ten parts of 3 chloro-4-cyano-S-dicyanomethylene-2- oxo-3-pyrroline is dissolved in 1566 parts of acetonitrile. To this solution 5 parts of Z-rnethylene-l,3,3-trimethylindoline (Fischers base) is added. The solution is heated at -60" C. and within a few minutes 4-cyano- 5 dicyanomethylene 2 oxo 3 (1,3,3 trimethyl Z-indolinylidene)methyl-S-pyrroline forms as a purple dye. Acetone is added and the resulting dye solution shows absorption maxima at 591 and 360 millirnicrons with relative intensities of 192.3 and 35 respectively.

The following table shows additional dyes prepared by the procedure of Example XII. In each preparation 5 parts of the indicated color former is used in place of the 2-methylene-l,3,3-trimethylindoline in Example XII. The products formed, their color and absorption characteristics in acetone/acetonitrile solution are indicated in tabular form. In the absorption column an asterisk indicates that the particular absorption maximum appears as a shoulder on another band and numbers in parentheses are relative intensities, comparable only within the spectrum of a single compound and not between compounds.

TABLE I Acetone/acetonitrile solution Structure of 3-substituent in 4-cyano-5- Example Color former dicyanomethylene-2-oxo-3-pyrrohne Name of dye Absorption Color maxima (millimlcrons) XIII. N-methyl-N-flcyano H30 4- cyano 5 dieynnomethylene -2- Blue 585(58) ethylaniline ox0-3- (p-[N-methyl-N-B-cyano- 383 (43.2)

ethylaminolphenyl) -3-pyrroline N C-C H2-CH2 XIV Furylacrolein phenyl- 4 eyano 5 dicyanomethyleue- 2 Green hydra zone oxo-3-(5-[&phenylhydrazonopropenyl]-2-furyl) -3-pyrroline C H NHN=G HCH=CH XV Pyrrole-2-aldehyde di- 4 cyano 5 dlcyanornethylene 3 -do 6800.8; methylhydrazone (5{dimethylhydrazonomethyl] 400 (1 .4

CH NN O H 2-pyrryl) -2'0x0-3-pyrrolino 3)2 111 H XVI Z-methylfuran 4- cyano 5 dieyanomethylene 3 Yellow-orange 470(2s3) (5-methyl-2-turyl) -2-ox0-3-pyr- 338 I c roline 1' s O XVII 2methylthiophene 4 eyano 5 dicyanomethylene 3 Orange 470 (248) (5-metliyl- Z-thienyl) 2- oxo-3- 410 pyrroline 385(162) H30 5 13 14 TABLE ICont inued Acetone la cetonitrile solution Structure of 3-st1bstitnent in 4cyauo-5- I Example Color former dleyanomethylene-2oxo-3-pyrroline Name of dye Absorption Color :m'axima (millimicrons) XDIV Aniline H S-anilinb-4-oyano-5=dicyanometh- Yellow. 415

l ylene-2-oxo-3-pyrrolino.

X LV N-meth ylaniline 13 H3 4 oyano 5 dieyauomethylene 3 -d o 425 I (N -methylaui1ino) -2-oXo-3-pyrroline.

XLVI m-Diethylaminophenol 4-cyano 5dicyanomethylenerll-( i- Blue 600(2.46) EQN- diethylamino-Z-hydroxy- 508(2.32) I pheuyl)-2-oXo-3-pyrroline. 370(3.12) on XLVII Phenol 4-cyano-5-dicyanomethylener3-(p- Magenta '700(2.7) HO hydroxyphenyl)-2-oxo-3-pyrro- 550(1 .78) line. 372(20.6) XLVIII- Furun 4-eyano-5-dicyanometl1ylene-3-(2- Yellow 435 I furyl)-2-oxo3-pyrroliue.

XLIX 'lhiophene 5 4-eyano-5-dicyanomethylene-2- grey-magenta 640 m J7 oxo-3-(2-thieny1)-3-pyiroline.

L Toluene 4-eyano-5 -dicyanomethylene-2.- .do 17020.24) H? oxo-3-(p tolyl)-3-pyrroline. 504(0.89)

o= /=OCN f \CN H 3 chloro 4 cyano 5 dicyanomethylene 2 0x0- 3-pyrroline (408 parts) and beuzaldehyde phenylhydrazone (392 parts) are dissolved together in 10,000 parts of acetonitrile. Reaction takes place rapidly at room temperature and is substantially complete within a few minutes. About 325 parts of crude 3-p-(benzylidinehydrazino)phenyl 4 cyano 5 dicyanomethylene 2- oxo-3-pyrroline is collected by filtration as a crystalline precipitate. A portion of this product is dissolved in boiling acetic acid to give a green solution showing absorption maxima at 605, 580, 455 and 346 millimicrons with molecular extinction coelficients of 10,900, 10,200, 14,600 and 14,600 respectively.

When N-(p-aeetylethy1)-N ethylaniline or N- (p-et hoxyethyD-N-ethylaniline is substituted for /3-(N-ethylanilino)- ethyltrimethylammonium chloride'in-Example LII, there is obtained 3-(p-[N-( 3-acetylethyl)-N-ethylamino].phenyl)-4-cyano-5-dicyanomethylene-Z-oxo-3-pyrroline or 4- cyano 5 dicyanomethylene 3 (p [N (p ethoxyethyl) -N-ethylanilino] -phenyl) -2-oxo-3-pyrroline respectively.

EXAMPLE LIII Cl-=.-COOC:H5 O=LN/=O COOC2H5 UN A solution of 52 parts of sodium in 553 parts of absolute ethanol is cooled to 0 C. To this solution is added 184 parts of the dimer of ethyl cyanoacetate (EtOOC-C(CN) =C(NH )CH COOEt Baron et al., '1. Chem. Soc. 85, 1736 (1904)) and 166 parts of diethyl oxalate. After standing three hours at room temperature the mixture is poured into 2640 parts of benzene and filtered. Evaporation of the solvent yields 340 parts of the 'disodium salt of S-(ot-CYElIlO-aethoxycarbonyDmethylene 4 ethoxycarbonyl 3 hydroxy-2-oxo-3-pyrroline.

The disodium salt parts) is treated with 200 parts of phosphorus oxyc'hloride in 391 parts of acetonitrile. The mixture is cooled at 0 C. during the spontaneous reaction and then let stand overnight at room temperature. Crystalline 3-chloro-5- (a-cyano-u-ethoxycarb onyl) methylene-4ethoxycarbony1-2-oxo-3-pyrroline is obtained by filtration and drying.

EXAMPLE 'LIV CHz 1 CN H To a solution of '5 parts of 3-chloro-5-(a-cyano-aethoxycarbonyhmethylene 4 ethoxycarbonyl 2 oxo- 3 -pyrroline in 780 parts-of acetonitrile is added 5 parts of Z-methylene-1,3,3-trimethylindoline (Fischers base).

5 (a cyano a ethoxycarbonynmethylene 4- To a solution of 46 parts of sodium in 3947 parts of Y 1 :Y} 2 Q 3 tTimBQIYIQ-iBdOHH- ethanol is added 132 parts of malononitrile dimer and 131533312211 11333532215;figl iliiiria ii l l iil 113 ethyl phenylglwfylam (ethyl 360 minimicmns zoylfonmc acid). The solution warms spontaneously The process of Example LIV is repeated using other and turns yellow. After one hour the solution is poured color formers in place of Fischers base. The formulas into 20,000 Parts of Water and acidified with aqueous yand colors of the resulting dyes are shown in Table II. drochloric acid. 4-cyano-S-dicyanomethylene-IZ-oxo-3- TAB LE II Solution Structure of Bsubstituent in 5- (aeyano-a-ethoxy- Example Color former carbonyl)methylene-Aether:ycarbonyl-2-oxo-3- Name of dye Absorppyrroline tion Color maxirna (millimicrons) LV y 5 (a oyano a ethoiwc-arbonyl) Red orange. 482(108) methylene-4-ethoxyearbonyl2- 340(84) I oxo-S-(2-pyrrolyl)-3-pyrroline. N 1 H L y r y T 5 (o: cyano a: ethoxyearhonyl) Blue 64o methylhydrazone. I methylene-3-(5-[dimethylhydrazonornethyl] -2-pyrro1yl) -4-eth- HxW N= H N oxyearbonyl-2-oxo-3-pyrroline.

l H LVII. Ethyl ester of benzoy 0 3- (1 -be11zoyl-1 -etl1oxycerbonyl) Yellow acetic acid methyl 5 (a eyeno a ethoxy- O carbonyl) methylene 4 ethoxy carbonyl-2-oxo-3-pyrroline.

/C H- C zH-C O LVIII-.. Furylacrolein pheuyl- 5 (aoyano 0: ethoxyearbonyl) Blue 590(97) hydrazone. methylene-4-ethoxycarbonyl-2- 367(420) oxo 3 (5 [3 phenylhydrazono CQH5NHN:CH OH:CI'I propenyH-Z-furyl)-3-pyrr0line.

LIX..- N,N diethyl a -neph C2115 5 (a c-yano a ethoxyearbonyl) Purple 570(21) thylamine. methylene 3 (4 N,N (liethyl 317 (875) N- amino 1 -naphthyl) 4 ethoxy carbonyl-2-oxo-3-pyrroline. CzHs LX 1,1-bts(p-N,N- 1i y 5 (oz oyano 0: ethoxycarhonyl) Green 605 aminophenyl) ethyl- (0 H3) :xN- I methylene -3 (2,2 bis[N,N di- 340 ene. methylamiuophenynvinyl) 4 C=CH ethoxyearbonyl 2 0x0 3 pyrroline. (C H 2N LXI..-.- N -n-butylcarbez0le 3-(9-N-butyl-3-oarba2olyl) -6- (a- Yello vcyano-wethoxycarbonyl)-meth ylene-4-ethoxycarbonyl2-oxo- 3-pyrreline.

N HaCHeCHaCHs LXIL--. 1 (p-tolylamino) -7- (p- 5 (zxcyano aethowoarbonyl) Orange tolyl1min0)-l,3,5 0y HaC- methylene-4-ethoxyoarbonyl-2- cloheptatriene. N= oxo-3-(l -lp-tolylamino] -7- [p- N tolyliillililo- 13,5 1- cyclohepta t en ro ine.

LXIII..- N (flbenzoyloxyethyl)-. 3 (p [N [3 benzoyloxyethyl N Red 550(45) N-ethylanilme. C 0 O C H; 0 H2 ethyllaminophenyl)-5-(a-cyano- 350() a-ethorwearbonyl) methylene-4- N- ethoxycarbonyl 2 0x0 3 pyr roline. C Ha C Ha I EXAMPLE LXIV phenyl-3-pyrroline forms as a bright yellow precipitate 0N 70 which is collected by filtrate and dried. Yield parts.

ON After recrystallization from aceticaeid, the product melts at 296-298 C. with decomposition.

N Analysis-Calcdfor C H N O: C, 68.3; H, 2.4; N, ON 7 22.8. Found: 0, 68.0; H, 2.7; N, 22.5.

A mixture of 155 parts of the sodium salt of malononitrile dimer and 117 parts of the methyl ester of N- methyl-oxamate in 1957 parts of acetonitrile is stirred 20 and heated at reflux for 16 hours. The mixture is filtered and the filtrate evaporated to dryness. The remaining solid is treated with a mixture of phosphorus oxychloride and N,N-dimethylaniline to obtain 4-cyano-5-dicyano I methylene 3-(p-N,N-dimethylaminophenyl)-l-methyl-2- 25 oxo-3-pyrroline as a bright blue dye.

EXAMPLE LXVI N as To a suspension of 410 parts of the monosodium salt of 5-(ez-cyano-a-p-toluenesulfonyl)methylene-3-hydroxy- 2-oxo-4-p-toluenesulfonyl-3-pyrroline (Example II, Part B) in 1957 parts of acetonitrile, 298 parts of oxalyl, chlo- 40 ride is added slowly with stirring. The mixture is allowed to stand at room temperature for one hour and then filtered. The filtrate is evaporated to dryness to yield 161 parts of crystalline 3-chloro-5-(a-cyano-a-p-toluenesulfon- 18 EXAMPLE LXVII H3O CH2 M3 HsC O- N =C S0zCHa CN H To a solution of 50 parts of 3-6111010-5-(0t-CY21I10-u-P- toluenesulfonyl)methylene 2 oxo-4-p-toluenesulfonyl- S-pyrroline in 900 parts of ethyl acetate is added about 50 parts of N,N-dimethylaniline. The mixture is allowed to stand for four hours at room temperature. The resulting precipitate is collected by filtration, washed with ethyl acetate and dried to'obtain 15 parts of 5-(a-cyano-u-p toluenesulfonyl)methylene 3 (p-N,N-dimethylaminophenyl)-2-oxo-4-p-toluenesulfonyl-3-pyrroline in the form of iridescent green-gold needles.

Analysis.Calcd for C H N O S C, 61.43; H, 4.57; N. 7.67. Found: C, 61.32; H, 4.59; N, 8.06.

EXAMPLE LXV III To a solution of about 5 parts of 3-chloro-5-(a-cyanoa p-toluenesulfonyl)methylene-2-oxo-4-p-toluenesulfonyl-3-pyrroline in about 50 parts of acetonitrile (containing a trace of pyridine) is added about 5 parts of malono nitrile. The solution rapidly turns orange with the formation of 5-(a-cyano-vt-p-toluenesulfonyl)methylene-3-dicyanomethyl-Z-oxo-4-p-toluenesulfonyl-3-pyrroline. The solution shows absorption maxima at 505 rnillimicrons and 480 millimicrons.

The following Table III shows additional dyes prepared by the process of Example LXVIII. In each preparation S-parts of the indicated color former is substituted for malononitrile in Example LXVIII. The products formed, their color and absorption characteristics in acetonitrile solution are indicated in tabular form. In

yl)methylene-2oxo-4-p-toluenesulfonyl-3-pyrroline. 45 Examples LXXI-LXXX the pyridine is omitted.

TABLE III Solution Structure of 3-substltuent in 5-(a-eyano- Example Color former a-p-tQluene-sulfonyl)methylene-Z-oxo- .Name 01' dye Absorp- 4-p-toluenesultonyl-a-pyrroline tion Color maxima (millimicrons) LXIX Benzoylaeetauilide O 3 [(benzoyl) (N phenylcarbamoyl) Red-orange..." 520 ,4 methyl] 5 (a eyano a p toluene 380 C sulfonyl)methyIene-2-0xo-4-p-tolu- \aH euesulfonyl-S-pyrrollne LXX a-Methyiluran 5-(qlh6}8110-G-DIZOIUGIIGSUIIODYI)-meth- Orange 520 ylene-3-(5-methyl-2-luryl)-2-oxo-4- 370 p-toluenesullonyl-3-pyrroline HaC Q LXXI N-methylanlllne H10 .5-(a?cyanomap-toluenesultony1)-meth- Yellow 420 yleue-3- (p-N-methylaminophenyl) [N 20x0.-4-p-toluenesulfonyl-B-pyrroline H LXXII, 2,6-dimeth-y1anillne, CH; 3-(4-amino-3,5-dlmethylphenyl)-5-(ado 396 cyano a p -t01uenesulfonyl) meth I ylene-2-oxo-4-p-toluenesulfonyl-3- HaN I pynoline TABLE III-Continued V Solution Structure of B-substituent in fi-(a-cyano- Example Color former a-p-toluene-sulfonyDmethylene-Z-oxo- Name of dye Absorp- 4-p-toluenesultonyl-a-pyrroline tion Color maxims (millimlcrons) LXXHI. Benzaldehyde phenyl- S-(a-cyano-a-p-toluenesulfony1)-meth- Yellow-orange 450 hydrazone NHN=CH ylene-20xo-3- (p-phenylhydrazono- 340 methyl)phenyll p-toluenesulfonyl- 3-pyrroline LXXIV-- m-Dlmethoxybenzene... 5-(a-cyano-a-p-toluenesulfonyl)-meth- Red-orange 475 HaC- y1ene-3-(2,4-dimethoxyphenyD-2- 356 x0-4-p-toluenesulionyl-3-pyrroline LXXV 1-methylamino-7-meth- -(a-cyanoa-p-toluenesulfonyD-meth- Yellow 415 ylimmo 1,3,5 cyclo- H: N ylene-3- (1-methy1amtno-7-1nethyl- 47 heptntriene tmlno-l,3,5-cycl0heptatrlen-4-yl)-2- 0x0-4-p-toluenesulionyl-3-pyrroline Hal-III LXXVI-.-.. l-benzylthio-I-(p-tolyl- 3-(1-benzylthto-7-[p-tolylimtnol-l 3 5- do 376 imino)-1,3,5-cyclohep- HIC N cycloheptatnen-4-yl)-5-(a-cyanb-iztatriene p-toluenesulfonyl)-methylene-2-oxo- 4-p-toluenesultonyl-B-pyrroline LXXVII--.- PyrroleZ-aldehyde di- 6-(a-cyano-a-p-toluenesulionyl)-meth- Blue 610 methylhydrazone l l ylfieuze-3-(5-dguathylhydraztinomegi- 4 y -pyrry -oxo-4-pouenes (CH;):NN=CH N V ionyl-B-pyrrollne LXXVIII--- Indole 5-(a-cyano-a-p-toluenesulionyl)-meth- Red 530 ylene-B-(El-indolyDQmxo-d-p-toluene- J sulionyl-il-pyrroline III H LXXIX...-. 2-methylene-1,3,3-tnfi-(u-cysno-a-p-toluenesulionyl)-meth- Purple 4 methylindollne ylene-2-oxo-4-p-toluenesuliouyl-3- 515 CH: (1,3,3 trimethyl 2 indolylldene) methyl-3-py'rroline OH- N 43H: LXXX Malononltrlle dimer.-. NC NH: 3-(l-amlno-Zg-dieyanovinyl)-cyano- -Red 490 methyl-5-(a-cyano-a-p-toluenesul- 350 iorignnieghylenefii-oxo-l-p-toluene- NC so onypyrro e The colors indicated for the solutions of the above dyes are obtained on cellulose acetate and nylon fabrics when these dyes are applied according to the procedure 0t Dyeing A, above.

As shown in the examples above, 3-chloro-4-cyano-5- dicyanomethylene-2oxo-3-pyrroline is an unusually active coupling agent. The similarly active 3-bromo-4-cyano- 5-dicyanomethylene-2-oxo-3-pyrroline is obtained by employing a brominating agent such as phosphorus tribromide, phosphorus oxybromide, thionyl bromide or the like in place of oxalyl chloride in Example IV.

In a similar manner when phosphorus oxybromide is used in place of phosphorus oxychloride in Example LIII, 3 bromo 5 1 cyano-a-ethoxycarbonyl)methylene-4- ethoxycarbonyl-2-oxo-3-pyrroline is obtained. Also, when thionyl bromide is used in place of oxalyl chloride in Example LXVI, 3-bromo-5-(u-cyano-u-p-toluenesulfonyl)methylene-Z-oxo-4-p-toluenesulfonyl-3-pyrroline is obtained.

(his ONE: 0: =c c0NHi l ON II The dimer of ethyl cyanoacetate is treated with concentrated ammonium hydroxide (Wagner and Zook, Synthetic Organic Chemistry, John Wiley and Sons, 1953, Method 352, page 568) to obtain 3-amino-2-cyano- Z-pentene-LS -dioic acid diamide (i.e., the dimer of cyanoacetamide). This is substituted for the dimer of ethyl cyanoacetate in the process of Example LIII to obtain 4-carbamoyl-5-(a-carbamoyl-a-cyano)methylene- 3-chloro-2-oxo-3-pyrroline. When phosphorus oxybromide is used in place of phosphorus oxychloride, 3- bromo 4-carbamoyl-5-(a-carbamoyI-a-cyano)methylene- 2-oxo-3-pyn'oline is obtained.

3-amino-2-cyano-2-pentene-l,S-dioic acid diamide is heated with methylamine hydrochloride or dimethylamine hydrochloride (Wagner andZook, op., cit., Method 351, page 568) to obtain the corresponding bis(monomethylamidesyhor bis-(dimethylamide). Other substituted diamides are obtained by using the corresponding amines. In the process of Example LIII these diamides give 3- chloro 5 -(a cyano-a-methylcarbamoyl)-methylene-4- methylca'rbamoyl-Z-oxo-3-pyrroline and 3-Ch10rO-5-(acyano a dimethylcarbamoyl)methylene-4-dimethylcarbamoyl-2-oxo 3-pyrroline respectively as well as the other MeOCOCONI-ICHQ for ethyl oxalate in Part A of Example I. This salt is treated with oxalyl chloride as in Example IV to obtain 3 chloro-4-cyano-S-dicyanomethylene-1-methyl-2-oxo-3- pyrroline. When thionyl bromide is used in place of oxalyl chloride, 3-bromo-4-cyano-S-dicyanomethylene-1- methyl-2-oxo-3-pyrroline is obtained.

When the mono-n-butylamide of ethyl oxalate is employed in the procedures above, l-(n-butyl)-3-chloro-4- cyano--dicyanomethylene-2-oxo-3-pyrroline and l-(nbutyl) 3 bromo 4 cyano-5-dicyanomethylene-2-oxo- 3-pyrroline are obtained respectively. In a similar manner the monophenylamide yields 3-chloro-4-cyano-5-dicyanomethylene-Z-oxo-l-phenyl-3-pyrroline and 3-bromo- 4 cyano S-dicyanomethylene-Z-oxo-1-phenyl-3-pyrroline respectively.

Corresponding substitution of monohydrocarbylamides of alkyl oxalates for ethyl oxalate in Part B of Example 11 and in Example LIII yields to the corresponding 5- cyanomethylene 3 halogen -1 hydrocarbyl 2oxo-3- pyrrolines.

Dyes are obtained by reacting the chloro and bromo compounds noted above with any of the color formers shown in the previous examples. For example, when N,N- dimethylaniline is employed, 5-(a-cyano-wethoxycarbonyl) methylene-3- (p-N,N dimethylaminophenyl) -4-ethoxycarbonyl-2-oxo-3-pyrroline, S-(a-CYaIIO-a p toluenesulfonyl)methylene-3-(p-N,N dimethylaminophenyl)-2-oxo- 4-)p-toluenesulfonyl-3pyrroline, 4-carbamoyl 5 (oz-Calbamoyl-a-cyano)methylene-3 (p N,N dimethylaminophenyl)-2-oxo-3-pyrroline, S ba-cyano a methylcarbamoyl)methylene 3 p- N,N-dimethylaminophenyl)-4- methylcarbamoyl-2-oxo-3-pyrroline, 5-(0L-CY3J1O or a dimethylcarbamoyl)methylene-3-(p N,N dimethylarninophenyl)-4-dimethylcarbamoyl-2-oxo-3-pyrroline, 4-cyano- 5-dicyanomethylene-3-(p N,N-dimethylaminophenyl)-l methyl-2-oxo-3-pyrroline, l-(n-butyl)-4-cyano-5-dicyanomethylene 3 (p N,N-dimethylaminophenyl)-2-oxo-3- pyrroline and 4-cyano-5-dicyanomethylene-3-'(p-N,N-dimethylaminophenyl)-2-oxo-1-phenyl-3-pyrroline are obtained respectively. In like manner when l,1-bis(p-N,N- dimethylaminophenyDethylene is the color former, S-(acyano-u-ethoxycarbonyl)methylene-3-[2,2 bis(p-N,N-dimethylaminophenyl)vinyl] 4 ethoxycarbonyl-2-oxo-3- pyrroline, 5-(a-cyanoa-p toluenesulfonyl)methylene-3- [2,2-bis(p N,N-dimethylaminophenyl)vinyl]-2-oxo-4-ptoluenesulfonyl-3-pyrroline, 4-carbamoyl-5-(a-carbamoyb a-cyano)methylene-3-[2,2 bis(p N,N dimethylaminophenyl)vinyl]-2-oxo-3-pyrroline, 5(a-cyano-a-methylcarbamoyl)methylene-3-[2,2 bis(p N,N dimethylaminophenyl) vinyl] -4-methylcarbamoyl-2-oxo-3 -pyrroline, 5( ozcyano-a-dimethylcarbamoyl methylene-3-[2,2-bis (p-N,N- dimethylaminophenyl)vinyl]-4-dimethylcarbamoyl-2 oxo- 3-pyrroline, 4-cyano-5-dicyanomethylene-3-[2,2 bis(p- N,N dimethylaminophenyl)viny1]-1-methyl-2-oxo-3-pyrroline, l (n butyl)-4-cyano-5-dicyanomethylene-3-[2,2- bis(p-N,N-dimethylaminophenyl)vinyl]-2-oxo-3-pyrroline and 4-cyan0-5-dicyanomethylene-3-[2,2-bis(p N,N dimethylaminophenyl vinyl] -2-oxo-1-phej1yl-3-pyrroline are obtained respectively, the similar chloro and bromo starting materials yielding identical products from a given color former.

The foregoing detailed description has been given for clearness of understanding only and nounnecessary limitations are to be understood therefrom. The invention is not limited to the exact details shown and described for obvious modifications will occur to those skilled in the art.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows 1. Dyes represented by the formula wherein R is a member of the class consisting of hydrogen and hydrocarbon radicals X and X are members of the class consisting of CN, SO- R, COOR and CONR groups, and Q is a monovalent organic radical such that the corresponding compound QH will condense with benzene diazon-ium chloride to yield an azo dye.

2. Dihydrate of the monosodium derivative of 4-cyano- 5-dicyanomethylene-3-hydroxy-2-oxo-3-pyrroline.

3. 4-cyano-5-dicyanomethylene-3-(p N,N dimethylaminophenyl) -2-oxo-3 vpyrroline.

4. 3 chloro-4-cyano-5-dicyanomethylene-2-oxo-3-pwroline.

5. 4-cyano-5-dicyanomethylene-3-[2,2-bis(p N,N dimethylaminophenyl) vinyl] -2-oxo-3 pyrroline.

6. j3-[N-ethyl-N (p-[4 cyano-S-dicyanomethylene 2- oxo-3 -pyrrolin-3 -yl] phenyl) amino] ethiyltrimethylammontium chloride.

7. Process which comprises reacting a compound of the formula (hal)--:X

L /X 0: LC

1; ON wherein (hal) represents halogen, R represents a member of the class consisting of hydrogen and hydrocarbon radicals and X and X represent members of the class consisting of CN, -SO R, COOR and -CONR groups, with a compound of the formula wherein Q is a monovalent organic radical, the compound QH being capable of condensing with benzene diazoniurn chloride to yield an azo dye, whereupon a compound of the formula wherein Q, R, X and X have the same significance as above, is obtained.

8. Compounds of the formula W X X No references cited.

UNITE STATES PATENT OFFICE M TEFICATE 0F CORRECTION Patent Noe S OlQT OlS December 1L2 1961 Rudolph Ac, Carboni It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 22 lines 33 to 37 for that portion of the formula reading I I )f -C read =C\ CN CN same column .22 line 66, for 50 R read -"SO R.

Signed and sealed this 3rd day of July 1962a (SEAL) Attest:

ERNEST w. SWIDER DAVID LADD Aitesting Officer Commissioner of Patents 

1. DYES REPRESENTED BY THE FORMULA 